An optical fiber end part holding device includes a base providing a V-groove in which an optical fiber end part is mounted and a pressuring member providing a pair of inclined faces forming a V-shaped form that engages the V-groove and a level lower face that presses and applies pressure to the end of an optical fiber mounted in the V-groove. The pressuring member moves to press and apply pressure to the end part of the optical fiber, is able to rotate in the same direction as the longitudinal direction of the V-groove, and is constructed such that the width of the lower face gradually broadens from one end in the direction that is the longitudinal direction of the V-groove toward the other end.